HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 99/1/45    most recent 01289.2004v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Win, T. S. Articles by Marshall, J. M. Search for Related Content PubMed PubMed Citation Articles by Win, T. S. Articles by Marshall, J. M.

Contribution of prostaglandins to the dilation that follows isometric forearm contraction in human subjects: effects of aspirin and hyperoxia

Department of Physiology, Division of Medical Sciences, The Medical School, Birmingham, United Kingdom

Submitted 16 November 2004 ; accepted in final form 26 February 2005

In 11 healthy volunteers, we evaluated, in a double-blind crossover study, whether the vasodilation that follows isometric contraction is mediated by prostaglandins (PGs) and/or is O₂ dependent. Subjects performed isometric handgrip for 2 min at 60% maximal voluntary contraction (MVC), after pretreatment with placebo or aspirin (600 mg orally), when breathing air or 40% O₂. Forearm blood flow was measured in the dominant forearm by venous occlusion plethysmography. Arterial blood pressure was also recorded, allowing calculation of forearm vascular conductance (FVC; forearm blood flow/arterial blood pressure). During air breathing, aspirin significantly reduced the increase in FVC that followed contraction at 60% MVC: from a baseline of 0.09 ± 0.011 [mean ± SE, conductance units (CU)], the peak value was reduced from 0.24 ± 0.03 to 0.14 ± 0.01 CU. Breathing 40% O₂ similarly reduced the increase in FVC relative to that evoked when breathing air; the peak value was 0.24 ± 0.03 vs. 0.15 ± 0.02 CU. However, after aspirin, breathing 40% O₂ had no further effect on the contraction-evoked increase in FVC (the peak value was 0.15 ± 0.02 vs. 0.16 ± 0.02 CU). Thus the present study indicates that prostaglandins make a substantial contribution to the peak of the vasodilation that follows isometric contraction of forearm muscles at 60% MVC. Given that hyperoxia similarly reduced the vasodilation and attenuated the effect of aspirin, we propose that the stimulus for prostaglandin synthesis and release is hypoxia of the endothelium.

vasodilation; hyperemia; hypoxia; hyperoxia

This article has been cited by other articles:

				C. D. Bradford, J. D. Cotter, M. S. Thorburn, R. J. Walker, and D. F. Gerrard Exercise can be pyrogenic in humans Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2007; 292(1): R143 - R149. [Abstract] [Full Text] [PDF]